Solar panels are now commonplace as efficient, clean energy sources. A solar panel includes an array of solar cells covered by a transparent protective cover through which sunlight transmits to reach the solar cells. During use, the transparent protective cover outer surface may become dirty as a result of an accumulation of: dust, soil, tree debris, sand, moss, dirt, sap, bugs, bird droppings, water spots or mold, thereby significantly reducing the panel efficiency. In solar parks, where multiple solar panels are located, often in remote areas, routine cleaning is labor intensive, requiring cleaning crews to clean the panels several times per month at considerable cost. Furthermore, where solar panels are mounted high, for example on residential or commercial rooftops, the cleaning crews risk serious injury from falls.
Several solar panel cleaning devices are known and have been used with limited success to address the above noted problems. For example, many known cleaning systems use a water reservoir to spray the solar panel with a flocculent solution, but these are largely ineffective at cleaning the solar panels and are considered to be environmentally unfriendly. One additional device described in European patent application number EP2048455A2 to Diaz et al for “Automatic Solar Panel Cleaning System” uses roller cleaning brushes which, when activated by a rain sensor, roll across the surface of the solar panels to sweep away the debris which has accumulated thereon. The system of Diaz, while straightforward to operate, suffers from several important disadvantages. The roller brushes merely brush the debris along the surface of the solar panels and may leave behind residual debris. Furthermore, the rain sensor does not detect rain intensity; therefore it is likely that the system of Diaz would be less effective, since it is not designed to take advantage of the cleansing assist that adequate rain intensity provides.
Thus, there is a need for an improved solar panel cleaning device which addresses the above-noted problems.